Regulatory Matters - Other Regulatory Matters (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Apr. 30, 2023
Public Utilities, General Disclosures [Line Items]
Other customer-provided capital rate	5.20%	1.75%
Return on regulatory assets	$ 2,467		$ 2,304
Deferred derivative losses recovery period, current (in years)	1 year
Recovery period for deferred derivative losses (in years)	3 years
CECONY
Public Utilities, General Disclosures [Line Items]
Net regulatory assets	$ 1,138		1,150
CECONY | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Estimated capitalization costs				$ 75
CECONY | Subsequent Event | Maximum
Public Utilities, General Disclosures [Line Items]
Capital expenditures limit				$ 421
CECONY | Commodity
Public Utilities, General Disclosures [Line Items]
Recovery period (in years)	4 years
CECONY | Subsidiaries
Public Utilities, General Disclosures [Line Items]
Return on regulatory assets	$ 2,268		2,097
O&R
Public Utilities, General Disclosures [Line Items]
Net regulatory assets	21		22
RECO | Subsidiaries
Public Utilities, General Disclosures [Line Items]
Return on regulatory assets	$ 22		$ 21